The traditional method of rain water harvesting is the most effective and simple way to conserve the water. It facilitates utilization of rain water for domestic as well as agricultural purposes. For a rain water harvesting system, all we need is rain and a place to collect it. Typically, rain is collected on roof tops and other surfaces. We can direct water run off from this surface to plants, trees or lawns. Also it can be stored for future use. In the US, roof top rainwater is collected and stored in sump. In India this includes ponds which collect the runoff from small streams in wide area and stores water for future use. Rainwater harvesting has been used to provide drinking water, water for livestock, water for irrigation or to refill aquifers in a process called ground-water recharge. As rainwater may be contaminated, it is often not considered suitable for drinking without treatment. However, there are many examples of rainwater being used for all purposes